//注销
function logout(){
    if(confirm("是否注销?")){ //点击是后进入if
        //1去后端删除session
        jQuery.ajax({
            URL:"/user/js/logout",
            type:"POST",
            data:{},
            success:function(res){}
        })
        //2,跳转到登录页面
        location.href="login.html"
    }
}